Low-temperature solid-phase preparation method of vanadyl oxalate

Abstract

The invention belongs to the field of chemical engineering, and particularly relates to a low-temperature solid-phase preparation method of vanadyl oxalate, which comprises the following steps: uniformly mixing vanadium pentoxide powder and oxalic acid powder, and heating for reaction to obtain solid vanadyl oxalate; the particle size of the vanadium pentoxide powder and the particle size of the oxalic acid powder are both smaller than 1 mm. The temperature of the heating reaction is 40-95 DEG C. By reducing the size of the raw materials, the specific surface area and the surface free energy of the raw materials are increased, the reaction energy barrier is reduced, the solid-phase reaction temperature can be greatly reduced, lower-temperature preparation and higher conversion rate of vanadyl oxalate are successfully realized, and the preparation energy consumption and irritant oxalic acid steam volatilization are also greatly reduced. The preparation method provided by the invention is rapid in process, simple in procedure, mild in condition, high in expansibility and suitable for large-scale production.

Description

Technical Field

[0001] The invention belongs to the field of chemical industry, and in particular relates to a low-temperature solid-phase preparation method of vanadyl oxalate. Background Art

[0002] Vanadium is an important raw material that is indispensable to the development of modern industry, national defense and science and technology, and is known as the "MSG of modern industry". Vanadium-based compounds have important uses in many fields such as catalysts, metallurgy, electronics, new materials and new energy. Vanadyl oxalate (or vanadium oxalate), as a soluble low-priced organic vanadium compound, is a basic vanadium chemical raw material and an intermediate raw material for the preparation of high-performance vanadium products including vanadium dioxide.

[0003] Currently, most of the vanadium oxalate sold on the market is in the form of aqueous solution, with few solid products and high prices, especially high-purity solid products and liquid products are rarely sold, and the purity is mostly below 99.0%. The general method for preparing vanadium oxalate reported publicly uses oxalic acid and vanadium pentoxide to react in an aqueous phase to obtain an initial vanadium oxalate aqueous solution, and then filters the solid particles and adds water to adjust the concentration to obtain a vanadium oxalate solution product. Its related solid vanadium oxalate products must undergo processes such as continued heating and concentration, cooling and crystallization, separation and drying. However, this process has high energy consumption and a long cycle, and the heating and concentration of high-concentration vanadium oxalate is prone to hydrolysis, decomposition or carbonization, affecting the quality of the final product. The traditional solid-phase reaction preparation method requires a higher reaction temperature to overcome the energy barrier required for the reaction. The reaction temperature is generally above 100°C, and stirring is required to ensure that the reaction is complete. However, higher heating temperatures are prone to volatilization of oxalic acid or decomposition and discoloration of vanadium oxalate. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a low-temperature solid-phase preparation method of vanadyl oxalate, which has simple procedures and mild conditions and is suitable for large-scale, efficient and clean production of solid vanadyl oxalate.

[0005] The present invention provides a low-temperature solid-phase preparation method of vanadyl oxalate, comprising the following steps:

[0006] The vanadium pentoxide powder and the oxalic acid powder are mixed evenly, and heated to react to obtain solid vanadium oxalate;

[0007] The particle sizes of the vanadium pentoxide powder and the oxalic acid powder are both less than 1 mm; the temperature of the heating reaction is 40-95°C.

[0008] Preferably, the vanadium pentoxide powder is obtained by grinding and screening a vanadium pentoxide raw material; and the oxalic acid powder is obtained by grinding and screening an oxalic acid raw material.

[0009] Preferably, the sieve aperture of the grinding and screening of the vanadium pentoxide raw material and the oxalic acid powder is ≥40 mesh.

[0010] Preferably, the molar ratio of the vanadium pentoxide powder to the oxalic acid powder is 1:(2.5-3.5) in terms of V.

[0011] Preferably, the molar ratio of the vanadium pentoxide powder to the oxalic acid powder is 1:3.

[0012] Preferably, the temperature of the heating reaction is 60-90°C.

[0013] Preferably, the heating reaction time is 0.5 to 12 hours.

[0014] Preferably, the heating reaction time is 2 to 6 hours.

[0015] Preferably, the preparation method further comprises: crushing the obtained solid vanadyl oxalate.

[0016] Compared with the prior art, the present invention provides a low-temperature solid-phase preparation method of vanadium oxalate, comprising the following steps: uniformly mixing vanadium pentoxide powder and oxalic acid powder, heating reaction, and obtaining solid vanadium oxalate; the particle sizes of the vanadium pentoxide powder and oxalic acid powder are both less than 1 mm; the temperature of the heating reaction is 40-95°C. The present invention reduces the size of the raw materials, thereby increasing the specific surface area and surface free energy of the raw materials, reducing the reaction energy barrier, and thus greatly reducing the solid-phase reaction temperature, successfully achieving a lower temperature preparation and higher conversion rate of vanadium oxalate, and also greatly reducing the preparation energy consumption and the volatilization of irritating oxalic acid vapor. The preparation method provided by the present invention has a rapid process, simple procedures, mild conditions, strong scalability, and is suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0018] Figure 1 This is a macroscopic sampling photo of the solid vanadyl oxalate product provided by the present invention;

[0019] Figure 2 is the XRD spectrum of the solid vanadyl oxalate product provided in Example 1 of the present invention;

[0020] Figure 3 is the XRD spectrum of the solid vanadyl oxalate product provided in Example 2 of the present invention;

[0021] Figure 4This is the XRD spectrum of the solid vanadyl oxalate product provided in Example 3 of the present invention. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The invention provides a low-temperature solid-phase preparation method of vanadium oxalate, comprising the following steps: uniformly mixing vanadium pentoxide powder and oxalic acid powder, heating for reaction, and obtaining solid vanadium oxalate.

[0024] In the preparation method provided by the present invention, the particle size of the vanadium pentoxide powder is less than 1 mm; the vanadium pentoxide powder is preferably obtained by grinding and screening the vanadium pentoxide raw material; the mesh size of the grinding and screening is preferably ≥40 mesh, more preferably 40-200 mesh, specifically 40 mesh or 100 mesh.

[0025] In the preparation method provided by the present invention, the particle size of the oxalic acid powder is less than 1 mm; the oxalic acid powder is preferably obtained by grinding and screening the oxalic acid raw material; the sieve aperture of the grinding and screening is preferably ≥40 mesh, more preferably 40-200 mesh, specifically 40 mesh or 100 mesh.

[0026] In the preparation method provided by the present invention, the molar ratio of the vanadium pentoxide powder to the oxalic acid powder, calculated as V, is preferably 1:(2.5-3.5), specifically 1:2.5, 1:2.6, 1:2.7, 1:2.8, 1:2.9, 1:3, 1:3.1, 1:3.2, 1:3.3, 1:3.4 or 1:3.5, and most preferably 1:3.

[0027] In the preparation method provided by the present invention, the heating reaction is a solid phase reaction, no additional solvent needs to be added, and no stirring is required during the reaction process.

[0028] In the preparation method provided by the present invention, the temperature of the heating reaction is 40-95°C, specifically 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C or 95°C; the time of the heating reaction is preferably 0.5-12h, specifically 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h or 12h.

[0029] In the preparation method provided by the present invention, it is preferred that the method further comprises: crushing the obtained solid vanadium oxalate to obtain a powdery or granular vanadium oxalate product.

[0030] In the preparation method provided by the present invention, the solid vanadyl oxalate product obtained is a dark blue solid. Figure 1 shown.

[0031] The preparation method provided by the present invention can significantly reduce the solid phase reaction temperature by reducing the size of the raw materials, successfully realizes the preparation of vanadium oxalate at a lower temperature, and significantly reduces the preparation energy consumption and the volatilization of irritating oxalic acid vapor. The method has a rapid process, simple procedures, mild conditions, strong scalability, and is suitable for large-scale production. The method breaks through the general thinking of existing ordinary technicians, breaks the technical prejudice of traditional chemical preparation, overcomes the shortcomings of existing synthesis or preparation technology, solves long-standing related technical problems, and obtains unexpected results.

[0032] For the purpose of greater clarity, the invention is described in detail through the following embodiments.

[0033] Example 1

[0034] A method for efficiently preparing vanadium oxalate by utilizing a small-scale effect, using vanadium pentoxide and oxalic acid as raw materials, and preparing the vanadium oxalate product by a low-temperature solid-phase reaction method, the steps of which include:

[0035] (1) sieving vanadium pentoxide and oxalic acid, and uniformly mixing vanadium pentoxide below 40 mesh and oxalic acid at a molar ratio of vanadium pentoxide to oxalic acid of 1:3 to obtain a mixture;

[0036] (2) placing the above mixture in a constant temperature chamber, controlling the temperature at 50° C., and reacting for 12 hours to obtain blue solid vanadium oxalate;

[0037] (3) Grind the above blue solid vanadyl oxalate into powder to obtain a powdery product with a purity of >98% and a yield of ∼100%.

[0038] Example 2

[0039] A method for efficiently preparing vanadium oxalate by utilizing a small-scale effect, using vanadium pentoxide and oxalic acid as raw materials, and preparing the vanadium oxalate product by a low-temperature solid-phase reaction method, the steps of which include:

[0040] (1) grinding and sieving vanadium pentoxide and oxalic acid, and uniformly mixing vanadium pentoxide below 100 mesh and oxalic acid at a molar ratio of vanadium pentoxide to oxalic acid of 1:3 to obtain a mixture;

[0041] (2) placing the above mixture in a constant temperature chamber, controlling the temperature at 90° C., and reacting for 2 h to obtain blue solid vanadium oxalate;

[0042] (3) The above blue solid vanadyl oxalate is crushed into particles to obtain a granular product with a purity of >99.5% and a yield of ∼100%.

[0043] Example 3

[0044] A method for efficiently preparing vanadium oxalate by utilizing a small-scale effect, using vanadium pentoxide and oxalic acid as raw materials, and preparing the vanadium oxalate product by a low-temperature solid-phase reaction method, the steps of which include:

[0045] (1) sieving vanadium pentoxide and oxalic acid, and uniformly mixing vanadium pentoxide below 40 mesh and oxalic acid at a molar ratio of vanadium pentoxide to oxalic acid of 1:3 to obtain a mixture;

[0046] (2) feeding the above mixture into a rotary kiln, controlling the temperature at 70° C., and reacting for 2 hours to obtain blue solid vanadium oxalate;

[0047] (3) The above blue solid vanadyl oxalate is crushed into particles to obtain a granular product with a purity of >99% and a yield of 100%.

[0048] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A low-temperature solid phase preparation method of vanadyl oxalate, characterized in that: The following steps are involved: The vanadium pentoxide powder and the oxalic acid powder are mixed evenly, and heated to react to obtain solid vanadium oxalate; The particle sizes of the vanadium pentoxide powder and the oxalic acid powder are both less than 1 mm; the temperature of the heating reaction is 40-95°C.

2. The low-temperature solid phase preparation method according to claim 1, characterized in that: The vanadium pentoxide powder is obtained by grinding and screening the vanadium pentoxide raw material; and the oxalic acid powder is obtained by grinding and screening the oxalic acid raw material.

3. The low-temperature solid phase preparation method according to claim 2, characterized in that: The sieve aperture of the grinding and screening of the vanadium pentoxide raw material and the oxalic acid powder is ≥40 meshes.

4. The low-temperature solid phase preparation method according to claim 1, characterized in that: The molar ratio of the vanadium pentoxide powder to the oxalic acid powder is 1:(2.5-3.5) in terms of V.

5. The low-temperature solid phase preparation method according to claim 4, characterized in that: The molar ratio of the vanadium pentoxide powder to the oxalic acid powder is 1:

3.

6. The low-temperature solid phase preparation method according to claim 1, characterized in that: The temperature of the heating reaction is 60-90°C.

7. The low-temperature solid phase preparation method according to claim 1, characterized in that: The heating reaction time is 0.5 to 12 hours.

8. The low-temperature solid phase preparation method according to claim 1, characterized in that: The heating reaction time is 2 to 6 hours.

9. The low-temperature solid phase preparation method according to claim 1, characterized in that: Also includes: The obtained solid vanadyl oxalate is crushed.

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